Adjustment device



May 28, 1940. w. F. HELMOND I 2, ADJUSTMENT DEVICE Filed June 11', 1938INVEN OR WILLIAM F. HELMDND ,ATTQRN EY Patented May 28, 1940 PATENTOFFICE ADJUSTMENT DEVICE William F. Helmond, West Hartford, 001111., as-

signor to Underwood Elliott Fisher Company, New York, N. Y., acorporation of Delaware Application June 11, 1938, Serial No. 213,226

6 Claims.

This invention relates to an adjustment device and more particularly toan adjustment device having provision for selective adjustment of amultiplicity of parts to govern the operation of a series of spacedindependently movable members. Although the invention may be of somewhatgeneral application it has a particularly important relation totypewriting mechanism and more specifically therein to the adjustment ofthe throw-off timing for the various type bar actuators of apower-driven typewriter.

One reason for the special application of this invention to typewritingmechanism is its incidental or secondary advantage in reducing the noiseof impact when the power drive unit throws an actuator into contact withthe adjustment device as the latter is serving to effect disconnectionbetween the actuator and the power drive unit.

vIn a power-driven typewriter it is highly desirable that the mechanismcontrolling the throw of the type bars be disconnected at a definitetime relative to the position of the type head in its arc of travel tothe platen. Owing to link and lever connections conventionally employedin typewriter type actions and the power operating devices therefor, itis necessary to have individual adjustment for each type action wherebythe point of disconnection from the power unit may be adjusted to suit,and it is also desirable that when this adjustment has been made nounintended change shall take place as might be due to vibration or othercauses.

The present invention has, therefore, as its principal object theprovision of an adjustment device which shall be rigid. simple inconstruction, and inexpensive to manufacture. and in which theadjustment may be quickly and conveniently made and is assuredlymaintained- The present invention further relates to a simple andinexpensive method of making an adjustment device for use in atypewriter or other machine involving a series of spaced relatedoperating parts.

In the drawing wherein is illustrated one of various possibleembodiments of the invention and wherein the method of making such adevice is also indicated:

Fig. l is a diagrammatic view of the type action and platen of apower-driven typewriter in which the present invention is serving as athrow-off stop for the power-driven actuator.

Fig. 2 is a View showing the component parts of the invention in partialdisassembly.

'tively soft resilient pieces l5 are provided prefer- Fig. 3 is a viewin cross section of the invention as shown in Fig. 2 with the partsassembled and the method completed. The section is taken transverselythrough the median of one of the adjusting screws.

Referring now more particularly to the drawing, a channel memberpreferably of metal is indicated atv Ill. At spaced points along thecenter line of the base of the channel member tapped holes I I areprovided. Into each of these 10 holes a screw I3 is threaded until asubstantial portion of its threaded shank lies between opposite sidewalls M of the channel member. Relato rubber such reference is intendedto embrace any other material having similar characteristics ofplasticity and resilience so that it may be pressed into frictionalengagement with the surfaces of the threads of the screw and will serveto retard the rotation thereof.

The molded rubber pieces l5 are fitted into the spaces between thechannel side walls and the screw shanks with the groove I6 in positionto fit around the screw shanks. When in such po sition the side walls Mare pressed toward each other and set in that position as shown in Fig.3. This forces the rubber into the thread spaces as indicated at I! inFig. 3 except for a slight distance along the screw shanks where 4 thepieces l5 do not meetas indicated at I 8 in Fig. 3. The rubber stripsare held in the channel against displacement by the pressing in of theside walls M.

The screws [3 may be screw-slotted for appli- 46 cation of an instrumentfor rotation of the screw, either at the top or bottom. In the presentpreferred embodiment such slot is provided in the bottom of the screw asindicated at l9.

In Fig. 1 of the drawing a typewriter key lever is shown at 20 fulcrumedat 2| and held in its upper position against a stop 22 by a returnspring 23. One type bar of a conventional series is shown .at 24 pivotedat .25 and adapted for a movement to a platen 26 under control of asublever 27 pivoted at 28.

Each sublever has an actuator 28' pivoted on it at 29 and held upwardlywith its forward end 30 against a stop bar 3| by a spring 32. Eachactuator carries a pivoted pawl 33 adapted to be engaged by the teeth ofa toothed roller 34 which latter extends transversely of the typewriterand is journaled in the frame thereof and ordinarily continuously drivenby an electric motor.

The adjusting device heretofore described is indicated in its operativeposition in Fig. 1 at 35 and is used there to provide selectivelyvariable points for the throw-off of the actuators 28. As each key lever20 is depressed a hook 36 overlying a lug 3'! on the actuator 28' pullsthe actuator down around the pivot 29 and engages the toothed pawl 33with the drive roller 34. This advances the actuator forwardly until acam face 38 contacts the head of screw l3 whereupon further continuedforward movement of the actuator lifts it to disengage the pawl teethand allow spring 32 to restore it upwardly.

The temporary engagement of an actuator with the drive roller causes athrow of a related type bar to the platen. Obviously the force of impactis variable in accordance with the length of time or distance that theactuator is maintained in engagement with the drive roller. Variation inthese factors causes variation in the typing stroke and consequently oneletter may appear sharp and another may appear weak just as isfrequently noted in the operation of manually struck types.

If such condition is noted in a typewriter -equipped with the presentinvention the duration of the engagement between the pawl 33 and thefluted roller may be varied at will by rotating the appropriate screw I3in one direction or the other.

Having once made such an adjustment it is desirable to maintain itduring subsequent operation of the machine. The friction grip of herubber on opposite sides of the screw and over the area of the threadsis suificient to hold the screw against rotation under normal useconditions, and sound vibrations from impact of the actuator areabsorbed to a large extent by the rubber between the screw shank and thechannel member.

What is claimed is:

l. A row of spaced adjustment screws and a mounting therefor including achannel-shaped metal member through the base of which the screws arethreaded with the screw shanks between the channel side walls, a rubberstrip along each opposite wall of the channel and clamped by said wallsinto frictional engagement with the thread surface of the screws.

2. A row of spaced adjustment screws and a mounting therefor including achannel member through the base of which the screws are threaded withthe screw shank between the channel side walls, a rubber strip alongeach channel wall having spaced transverse grooves to fit the screws andbeing under pressure from the wall which forces the rubber intoengagement with a substantial area of the thread surface.

3. An adjustment device for engagement by separately operable parts in atypewriting mechanism, comprising a channel member adapted to be fixedto a supporting frame, a row of spaced screws threaded into the base ofthe channel and having their threaded shanks lying between the channelside-walls, a soft-vulcanized rubber strip on each side of the row ofscrews, held by the side walls in pressure engagement with all thescrews to the extent that the rubber of the strips is forced into thescrew thread spaces.

4. In a power-driven typewriter having a type action system including aseries of type bar actuators and a power roller cooperative therewith,an adjustable throw-off device adapted for engagement by the actuatorsand comprising an elongate channel fixedly mounted, a series ofthrow-off screws carried by said channel, and a body of resilientmaterial compressed within said channel and embracing said screws todampen impact of the actuators thereon and frictionally lock said screwsin adjusted positions.

5. In a power-driven typewriter having a type action system including aseries of type bar actuators and a power roller cooperative therewith,an adjustable throw-off device adapted for engagement by the actuatorsand comprising a fixedly mounted elongate channel having a base and sidewalls, a series of throw-off screws threadedly carried in said channelbase and projecting substantially between the side walls thereof, and apair of rubber strips, each disposed between a channel side wall andsaid screws, said strips frictionally engaging said screws to resistrotation thereof and dampen impact of the actuators thereon.

6. In a power-driven typewriter having a type action system including aseries of type bar actuators and a power roller cooperative therewith,an adjustable throw-off device adapted for engagement by the actuatorsand comprising a fixedly mounted elongate channel having a base and sidewalls, a series of throw-off screws having threaded shanks threadedlycarried in said channel base and projecting substantially between theside walls, and a pair of rubber strips having transverse groovesaccommodating the screw shanks, said strips being disposed at oppositesides of said screw shanks and compressed within said channel tofrictionally lock said screws against rotation and dampen impact of theactuators thereon.

WILLIAM F. HELMOND.

